Light emitting diode including a cover covering a light emitting diode element

Abstract

In an LED (Light Emitting Diode) including a cover covering an LED element, the cover is formed using glass having a composition R n SiO 2-n/2 . The glass according to the present invention is low melting point glass with a softening temperature of −40° C. to 300° C., melts at lower temperatures compared to conventional glass, and can safely form the cover without damaging the LED element. Since glass has better moisture shield performance and resistance to light compared to epoxy resins, the cover is formed using glass, and consequently deterioration of the LED element and a phosphor caused by moisture is reduced, deterioration of the cover caused by light is reduced, and changes in color and luminous intensity are restrained.

The invention claimed is: 
     
       1. A light emitting diode comprising:
 a light emitting diode element; and 
 a transparent cover covering said light emitting diode element partly or completely, 
 wherein said cover is formed using glass having a composition including R n SiO 2-n/2 , 
 where 0<n<4, R is at least one group selected from a phenyl group (C 6 H 5 —), an ethyl group (C 2 H 5 —), a methyl group (CH 3 —), a benzoyl group (C 6 H 5 CO—), a benzyl group (C 6 H 5 CH 2 —) and a vinyl group (CH 2 ═CH—). 
 
     
     
       2. The light emitting diode of  claim 1 , wherein
 the glass has a softening temperature ranging from −40° C. to 300° C. 
 
     
     
       3. The light emitting diode of  claim 2 , wherein
 the glass is capable of being re-melted repeatedly within the softening temperature range. 
 
     
     
       4. The light emitting diode of  claim 2 , wherein
 the glass is capable of being melted only a predetermined number of times within the softening temperature range. 
 
     
     
       5. The light emitting diode of  claim 1 , wherein
 said cover is formed by further adding one or a plurality of kinds of pigments, or a phosphor for converting an emission wavelength of said light emitting diode element, to the glass. 
 
     
     
       6. The light emitting diode of  claim 1 , further comprising:
 a lead frame having a recessed portion; and 
 a transparent mold for covering said recessed portion and said cover, 
 wherein said light emitting diode element is mounted on a bottom of said recessed portion, and said recessed portion in which said light emitting diode element is mounted on the bottom is filled with said cover. 
 
     
     
       7. The light emitting diode of  claim 6 , wherein
 said recessed portion is filled with said cover at a position closer to the bottom than a plane formed by a brim of said recessed portion. 
 
     
     
       8. The light emitting diode of  claim 1 , further comprising
 a wiring board, 
 wherein said light emitting diode element is mounted on said wiring board. 
 
     
     
       9. The light emitting diode of  claim 1 ,
 wherein said light emitting diode element has an emission wavelength of 280 nm to 450 nm. 
 
     
     
       10. A light emitting diode comprising:
 a light emitting diode element; and 
 a transparent cover covering said light emitting diode element partly or completely, 
 wherein said cover is formed using glass having a composition composed of a mole % of C 6 H 5 SiO 3/2  and b mole % of (C 6 H 5 ) 2 SiO, where a+b=100, 10≦a≦100, and 0≦b≦90. 
 
     
     
       11. The light emitting diode of  claim 10 , wherein
 a=60 to 90, and b=10 to 40. 
 
     
     
       12. A light emitting diode comprising:
 a light emitting diode element; and 
 a transparent cover covering said light emitting diode element partly or completely, 
 wherein said cover is formed using glass having a composition composed of a mole % of C 6 H 5 SiO 3/2  and b mole % of (CH 3 ) 2 SiO, where a+b=100, 10≦a≦100, and 0≦b≦90. 
 
     
     
       13. The light emitting diode of  claim 12  wherein
 a=60 to 90, and b=10 to 40. 
 
     
     
       14. A light emitting diode comprising:
 a light emitting diode element; and 
 a transparent cover covering said light emitting diode element partly or completely, 
 wherein said cover is formed using glass having a composition composed of a mole % of CH 3 SiO 3/2  and b mole % of (CH 6 H 5 ) 2 SiO, where a+b=100, 10≦a≦100, and 0≦b≦90. 
 
     
     
       15. The light emitting diode of  claim 14 , wherein
 a=60 to 90, and b=10 to 40. 
 
     
     
       16. A light emitting diode comprising:
 a light emitting diode element; and 
 a transparent cover covering said light emitting diode element partly or completely, 
 wherein said cover is formed using glass having a composition composed of a mole % of CH 3 SiO 3/2  and b mole % of (CH 3 ) 2 SiO, where a+b=100, 10≦a≦100, and 0≦b≦90. 
 
     
     
       17. The light emitting diode of  claim 16 , wherein
 a=60 to 90, and b=10 to 40.